1. Technical Field
The present disclosure relates to a polymerizable composition for coloring contact lenses. More particularly, the polymeriazble composition for coloring contact lenses has good adhesion to the contact lenses so that no discoloration or fading occurred on the colored contact lenses made from hydrogel or silicone hydrogel.
2. Description of Related Art
Nowadays, concerning fashion or clothes matching, people begin to wear colored contact lenses capable of altering their natural iris color. However these different colored or patterned contact lenses would fade or discolor so as to make the wearers have ocular allergy.
One of the conventional methods for manufacturing colored contact lens is to mix a colorant and the hydrophilic monomers to form a mixture, and then a colored layer is formed by printing or transferring the mixture on a surface of the contact lens. However, the method is unfavorable because the colored layer lacks the interaction force with the contact lens, so that the colored layer is easily peeling from contact lenses and discoloration or fading occurs.
Another one of the conventional methods for manufacturing colored contact lenses is first to form a colored layer on the contact lens surface, and than a transparent layer is covered on the colored layer to protect the colored layer from being damaged and discolored. But, this method is so complicated and costly.
Therefore, a novel polymerizable composition for coloring contact lenses is highly demanded. The polymeriazble composition of the present disclosure provides good adhesion to contact lenses to avoid discoloration or fading on the colored contact lenses. In addition, the manufacturing method for coloring contact lenses of the present disclosure is simpler than the conventional manufacturing methods.